1. Technical Field
Embodiments of the invention relate to semiconductor packages and, more particularly, to semiconductor packages with optical interconnection structures, memory cards including the same, and electronic systems including the same.
2. Related Art
Semiconductor packages which are capable of processing a large amount of data are increasingly in demand with the development of smaller electronic systems such as mobile systems. In response to such a demand, it may be necessary to increase the integration density of semiconductor devices used in the electronic systems. However, there may be some limitations in increasing the integration density of the semiconductor devices. Recently, three dimensional semiconductor devices including vertical transistors instead of planar transistors have been proposed to increase the integration density of the semiconductor devices. Nevertheless, there may be a lot of technical difficulties in developing the three dimensional semiconductor devices.
Stack packages including a plurality of stacked semiconductor devices (also, referred to as semiconductor chips or semiconductor dice) have been proposed to process a large amount of data. Each of the stack packages may be fabricated by stacking a plurality of semiconductor chips on a single package substrate and by encapsulating the stacked semiconductor chips. That is, high capacitive semiconductor packages may be fabricated in a stack package form. In such a case, the number of signal paths (i.e., signal lines) for driving the semiconductor chips may increase in proportion of the number of the stacked semiconductor chips. Accordingly, it may be necessary to reduce a line width and a pitch of metal interconnection lines (corresponding to the signal paths) disposed on and in the package substrate in order to realize the high capacitive stacked packages.